1. Field of Invention
This invention relates to methods for packing, storing, and transporting fresh and processed fruits and vegetables, and particularly to methods for packing, storing, preserving, and transporting vegetables such as broccoli for international shipments and enabling achievement of foreign and domestic quarantine requirements.
2. Description of the Related Art
Various methods and apparatuses have been proposed and implemented to effect the packing, storing, and transport of fresh and processed fruits and vegetables. The exportation of fruits and vegetables from the United States has increased dramatically in recent years. One area of rapid increase is the exportation of broccoli to Japan, recently achieving a volume of over 200 42-foot refrigerated sea containers in one week. Each sea container typically contains from 912 to 960 cartons of broccoli. The broccoli carton is additionally completely filled with ice and this included weight limits the amount of broccoli that can be delivered in the sea container to the port, or other domestic destination, because of United States Department of Transportation safety standards with regard to maximum transportable weight.
Exporters of broccoli and other fruits and vegetables have been actively seeking other methods of delivering a greater number of vegetables in each container in order to reduce unit freight costs. One such approach uses controlled and modified atmosphere systems. The use of these controlled-gas systems retards the spoilage rate, or senescent decay of the vegetable, thus reducing the requirement for ice and the concomitant weight problems. However, such methods are limited by problems such as humidity control in transit, cost and technical requirements.
In the United States, over-wrap and shrink-wrap packaging films have long been used by shippers and retailers to maintain cleanliness and reduce moisture loss in the packaging, shipping and transport of fruits and vegetables. The use of shrink-wrap film has begun to increase dramatically as a method to increase domestic freight efficiencies and also to provide a more attractive and longer lasting product.
Both in the United States and Japan, retailers frequently over-wrap fruits and vegetables, and particularly broccoli, both domestic and imported, with plastic films to prevent handling abuse and to allow for placement of scanner tags or labels. Since labor cost are in general very high in Japan, there is great interest in receiving the product in that country in a wrapped state. Heretofore, however, this has not been possible because of the Japanese Plant Quarantine regulations.
The Plant Quarantine Department in Japan is charged with protecting their island country from pests or diseases common to agricultural crops in other parts of the world. Their zeal and conscientiousness in carrying out this mandate is high. One requirement germane to the present methodology is a requirement with regard to the ability of a packaged vegetable or fruit to undergo fumigation, where that may be required as a result of inspection. That is, any packaged fresh fruit or vegetable must have minimum of 2% open area on its container. This includes cartons, bags, over-wraps, etc. In the case of shrink-wrap protected products, this standard also applies.
Accordingly, there are broadly five difficulties which need to be resolved in formulating a method to satisfy the Japanese Quarantine requirements, which because or their rigorous nature, also will satisfactorily meet essentially all other quarantine and inspection requirements throughout the world:
i) hole size PA1 ii) change in shape and dimension PA1 iii) hole making PA1 iv) product damage PA1 v) hole blockage
With regard to (i) hole size; it must be adequate to consistently provide for open space in excess of 2%. If this is not satisfactory, and fumigation is called for, each wrap must be removed by hand salvage the product. Typically, the number of pieces may exceed 50,000 in a single container with prohibitive costs and product damage.
Regarding (ii) change in shape; shrinking of the film changes the shape of the hole or holes, resulting in enlargement of the hole where tension is developed, and shrinkage where tension is lacking. This presents a risk with regard to minimum open space and also to the Japanese Plant Quarantine inspection interpretation of net hole size.
As to (iii) hole making; the simple multiplication of pinholes is not a satisfactory method. The number of holes required may result in a web of film which is mechanically difficult to handle. In order to obtain the 2% coverage required in Japan, for example, there must be a pattern of holes such that their total open area relative to the final area of the shrunken film is at least 2%. For example, for a finished area of 600 square centimeters, a minimum of 12 square centimeters of open area is needed. For pinholes or punctures that are effectively 0.2 millimeters in diameter, approximately 400 holes are required. To account for changes in shape and product blockage of holes, a 10-fold multiple may be needed. Also, the use of these small holes is not productive since Japanese Plant Quarantine officials require a method that is straightforward and routine for examination of compliance.
With regard to (iv) product damage and (v) hole blockage; if numerous holes are placed throughout the film widespread and spotty decay of the open space areas of the fruit or vegetable may result, and lead to a net open area of the film being deemed insufficient by inspectors.
According, it would be highly desirable to have a method for eliminating the above described problems in the packaging, shipping and transport of fruits and vegetables. The present invention provides a simple but unique method to eliminate the above described problems and describes in particular, the placement of holes to take advantage of the morphological characteristics of broccoli and related vegetables so as to ensure that tension developed during shrinking of the film results in hole enlargement, and that the holes are spaced and positioned so as to prevent blockage by the product.
It is a further object of the invention to provide a method for packing, and transporting fruits and vegetables which allows such fruits and vegetables to be packaged and shipped over extended distances involving significant time periods while preserving all of the critical and important characteristics of such fruits and vegetables while guaranteeing a commercially attractive product, and which is inexpensive to apply and highly efficient in results.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the methods and combinations particularly pointed out in the appended claims.